Telescoping assemblies, comprising an inner tube and an outer tube telescopically received within the inner tube, coupled with a mechanism for maintaining a desired telescopic position of the inner tube relative to the outer tube. This type of telescoping arrangement is often used as an adjustable seat post for a bicycle seat.
One type of telescoping assembly relies on a support reservoir disposed between the inner tube and the outer tube for supporting the inner tube against the outer tube. In this type of telescoping assembly, the inner tube is slidably received within the outer tube and the support reservoir is in valve-governed fluid communication with a sink reservoir, each of which contains an incompressible fluid. By opening the valve, the position of the inner tube element relative to the outer tube can be adjusted. Moving fluid from the support reservoir to the sink reservoir will telescopically collapse the inner tube, and moving fluid from the sink reservoir to the support reservoir will telescopically extend the inner tube.
Another type of telescoping assembly uses mechanical obstruction to support the inner tube against the outer tube. With mechanical obstruction, one element extends into or across the path of motion of another element so as to obstruct that motion. For example, a radially outwardly extending detent may be removably received in a corresponding slot cut into the inside of the inner tube to resist longitudinal movement of the inner tube.
Yet another type of telescoping assembly uses hydraulic clamping to maintain a desired telescopic position, as taught by U.S. Patent Application Publication No. 2010/0052286.